Clicking noise in Carburator

[badgertom]

I noticed a clicking noise in the left cylinder. With an increase of the rpm the clicking noise increases as well. I assume the noise comes from the valve (opening and closing). Before I open open everything up what could possibly be loose? I believe the last time I adjusted the valves I tightened everything. What else could it be? 

[Tony Smith]

A missing needle roller in the rocker is always a good suspect - if it did prove to be that you will need to build a jig to press the old bearings out and the new ones in - not a difficult job. The other source of rattles and clicks is wear in the carb body where the butterfly spindle seats - You used to be able to buy oversized spindle kits which allowed you to simply ream out the worn holes to the right size but I have not seen them for a long time. a really loose one can kick up quite an annoying racket.

An exhaust leak can sound remarkably metallic as can a pinhole head gasket failure.